Shock-absorbing suspension system



F. L. O. WADSWORTH SHOCK ABsoRBINGJsUsPENs'IoN SYSTEM Filed April 11,H1922 4 sheets-sheet 1 Feb. z3 ,1926. 1,574,140

Feb. 23 1926.

F. L. o. WADSWGRTH HOCK ABSORBING SUSPENSION SYSTEM ril ll, 1922 I 4Sheeis-Sheet 2 Filed Ap Feb. 23 1926.

F. L. O. WADSWCRTH SHOCK AssoRBING SUSPENSION SYSTEM 4 Sheets-Sheet 3Filed April l1, 1922 Feb. 23 192e. 1,574,140I

F. L. O. WADSWORTH SHOCK ABSORBING SUSPENSION SYSTEM Filed April 11,1922 4 Shee,s-Shee1'l 4 .Patented Feb. 23, 1926.

i FRANK L. o. Wansvvonfrn, or rrfr'rsnnnen, PENNSYLVANIA. l

snoorr-azesonnme SUSPENSION sYsTnr/r.

Application led April 11, 1922. Serial No. 551,674.

To all 'whom-t may concern.'

Be it'lrnown that I, FRANK L. O.l VVADs- WORTH, a citizen of the UnitedStates, residing at Pittsburgh, Pennsylvania, Vhave inventer a `new anduseful Improvement in Shock-Absorbing Suspension Systems,vof which thefollowing` is a full, clear, and exact description, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to shoclr absorbing` suspension .systems forvehicles of various lrinds and has for'ts object the provision of asimple and rel'able combination of primary and secondary springs whichwill elflciently cooperate, and complement each other, in cushioning andabsorbing'both the minor and the major vibrations, oscillations, andshocks, to which the vehicle wheels and ruiming gear are subjected inpassing over irregular road surfaces; and which will thus effectivelyprevent or restrain any unpleasant or dangerous movements of theelastically supported body portions of the vehicles.

Another object of my present improvements is the utilization of a singlesecondary or supplemental spring for elastically restraining, both therelative approach of the running' gear and tonneau members of thevehicle chassis, and also the rebound or recoil of those members aboveor beyond the Vnormal or static load position. A further objet-t of theinventionv is the ar 'angement of one or more pairs of such.supplemental springs in such relation tothecoacting parts ofthe systemas to effectively resist and checlrany lateral displacement of the bodymembers on the running gear supports.

Still another specific object of these improvenients is the frictionaldampingof the recoil movements of the secondary suspensionl springs forthe purpose of diminishing they range and the Frapidityl of the-oscillation or vibration of these resilient elements and thus reducingor eliminating the effects ofercessive rebound movements.

'A further specific feature of my present invention is the use of asecondaryor supplemental leaf spring member in such manner as to utilizethe transverse elasticity of the spring in resisting ycompressivemovements of the system and to utilize the longitud'nal resilience ofthe leaf elements in reforms of secondary4 leaf spring elements; Y

Fig. 2 is a corresponding View of the other side of this system withthel parts in the position of extreme rebound; Fig. 3 is anV enlargedsectional view of la portion of the construction shown .in Figs. lfand 2and shows a modified form of the link connec- 7 tion between thesecondary leaf spring element and the body member of the vehicle; Fig. 4is an enlarged front elevationof the same form of suspension that isillustrated in Figs. l and Zand depicts still another modification ofthe said link connection; v'Fig. 5 is a rear elevation of across leafspring suspension 'system for the rea-r axle mounting of a Ford car;Fig. 6 in a'correspending view of thissame system with the parts thereofin the postion of extreme compression; and Figs. 7,V 8 and 9illustrateanother exemplification of my invention as ap-. plied to thefront cross leaf spring' of this type of vehicle.

Fig. l0 is an eleyation of the rear portion of a side leaf springsupport which is pro. vided with my improved Vsecondary springsuspension; Fig. l1 is a sectional view of a portion of this secondarysuspension mechanism with the parts thereofin the rebound position ;lFig. l2 is an elevation of another side leaf spring suspension`embodying myV improvements; and Fgl is a similarv view of a cantileverspring system thatA comprises still another form ofl my` invention.AFigs. lei-l5 and leeldepicttwo other exempliiications of the` presentimprovements as applied to the, cross leaf spring supportfor the frontaxle of motor vehicles and Figs. 18, 19 and 20 illustrate still anotherembodiment of these improvements as they may be utilized in `conjunctionwith a` similar cross-leaf spring support for the rear axle of thevehicle; Fig. 21 is an enlarged sectional view of apart of the secondarysuspension construction which is shown in Figs. 18, 19 and 20, and-whichmay also be used in conjunction with other exemplifioations of myimprovements; Figs.

22 and 23 illustrate a secondary suspensionl construction similar tothat depicted in Figs. 18 to 21, as applied to either the front or rear:side leaf spring members of a chassis iframe', Fig. 24 is an elevationof another side leaf spring system in which a somewhat diiterent torm ofsecondary suspension construction is employed; Fig. 25 is Vva simi- `larview-'in partial section-of this last construction with lthe members in'the `posi- 'tion 'ot `lextreme compression; Fig. 26 is a transversesection on the plane 26-26 ot Fig-24; Figs`27-2S and 29 illustrate aturther modification ot my improvements yas-applied to a'fspring shackle`support for cross leat' '(or k:side leaf) springs; and Figs. 30 and 31depict an additional exemplitication of this last application lof myinvention.

yIn the construction shown in Figs. 1 and 2 the shackle links at theiends of the main 'cross ilea'r spring 1 are coupled to the intermediatelportions of lever members 2, 2; and the latter arein turn pivotallysupported at their outerlends, on the reversed axle perches 3, 3. 'Theseylevers carry the thick' ends of flexible supplemental lcat' springs 4 4which are conjoined, at their inner. eye ends, to the body members ofthe vehicle, 'by `means of the lbell crank link connections 5, o. Thelink elements 5, 5,'are provided with adjustable stops 6-6 which areadapted to engage with the body support', on which 'the said elementsvare pivoted, and -thereby limit the outward swinging movement of thelink ends to which the supplemental lsprings 4.-4 are connected. hestops 6, 6 are. so set as to make contact engagement with the body whenthe secondary springs are subjected to such initial tension Y l,oriiexure, as will sutice to maintain the `ip'arts in the position ofstatic equilibrium (N)-as shown in Fig. 1.

The operation ot this system is as tol- 'lowsz When the running gear ortonneau members are subjected to a kinetic' compression stresswhichtends to move them toward -each other-the shackle links at the ends-ofthe main spring 1 exert an increased pull yon the levers '2-2, and thesecondary springs attached thereto, and lproduce an increased tlexurerotthe latter elements that Ystraightens them out and carries Ythemdownward toward'the dotted line position C-C'oif Fig. 1. This movementrocks the `link connections 5 5 inwardly and disengage the stops 6.-6Jfrom contact with `the body support. Vhen the increased kinetic loadstress is relieved the iexed supplemental springsl 5-5 will recoiltoward the normal load position of Fig. 1, but this re- "turn movementis damped yand retarded by Lshown in Fig. 2. Inthis separation ot thechassis parts the links 5-5 will be held against further outwardmovement by the engagement of the stops '6, 6, with the body member ofthe vehicle; and the resultant connected motionl of the interlocked linkand body elements away from the ax-le perch supports 3 3, will exert alongitudinal or endwise pull on the bowed leafv springs 4 4, that willflatten or straighten them out to the `form shown in fulllines in Fig.2. This action will elastically resist any rebound or separation of theconnected body and axle members, and will quickly check any suchexpansion ot the suspension system without imposing `any substantialreverse strain or flexure, on the ma'in spring` member 1.

It will be observed that in both the normal and the expanded positionsof tbe chassis members the body ofthe vehicle is always subjected to twooppositely directed and symmetrically applied forces-viz', the.longitudinal tensions of the ltwo symmetrically disposed secondary leafsprings e-ll, that are transmitted to the body through the links 5-5 andthe stops 6, G-which tendv to lhold it centered with respect to the axlesupports 3, 3, and to strongly resist any side sway .or rolling of thetonneau on the running gear trame. This secondary spring restraintagainst relative lateral movement ot the chassis members rapidlyincreases as 'the expansion movement continues; and at the two stronglyflexed 'and opposiiely inyclined leaf springs et, 4;, willact almost asetectively as rigid braces inpreserving an exact centering ot' the bodybetween the axle perches $3, B. When the parts are in a position ot'compressionand the tonneau and the runninggear supports are relativelyclose together-side .sway is 'less objectionable; and in this Vposition(as indicated in ydotted'lines in Fig. 1) the body is held in its`centered relationship to the axle perches by the syn'nnetrical pull ofthe oppositely inclined link connections 5, 5, and by the increase inthe longitudinal stress on one ot the supplemental springs, as comparedwith the other. whenever the body swings away from this centralposition.

In the construction shown in Figs. l and l the daniiping ot the recoilmovements ot the secondary springs is eiected entirely by the irictionalresistance to the relative longi tudinal slip et the pressure engaged.leaves ot these resilient elements; and in the casel of such highlytlexible and strongly bowed springs as l preier to employ in the saidconstruction this relative slip is suriiciently large to producea verymarked and substantial damping ol" the spring` movements. But in orderto supplement this damping action l may in some cases, use the term ot'link connection shown in section in Fig. 3. rlhis comprises a` camshaped link 5% that is pivoted between the sides oit a hollow bracket 8,(which is riveted, or otherwise suitably .secured to the body gt'ranie)and a wedge 'shapedblock 9 which is slidably mounted in the bracket 8and is l against the curved cam lace ot the linll;` by the spring l0.The ripper toe end ot the cam link is provided with a shoulder ll whichis adapted to engage with the adjacent end or the wedge block 9 when theparts are in the normal (dotted line)A position oft Fig. 35

and in this position the link and blcck elements are locked againstfurther relative movement in the bracket and body supports by theengagement ot an adjustable screw stop 6Z1 with the lower recessed endof the block 9. l/Vhen the body and axle members are forced toward eachother the increased llexure ot the secondary spring a-which is attachedto the lower end ot the link element '5a-swings the said link inwardly,toward the lull line position et Fig 3, and permits the spring l0 topush the block i) upwardly against the head ot the cam `tace. lVhcn therecoil or return movement begins the reverse motion ot the engaged camand block elements is retarded or damped by the 'lirictional resistancebetween the relatively sliding surfaces oi' the said elements and thebracket support 8. This damping action on the swinging` movement of thelink `supplements the interleaf rictional retardation of the recoilingspring l and thereby assists in preventingl a too sudden reaction andoverthrow ot the compressed resilient susperr sion elements.

The construction shown in Fig. A: is substantially identical with thatshown in l and 2 with the exception ot the connection between thesupplemental leat spring l and he body frame. ln this ekainplaryillustration ot my invention the supporting link 5 is pivotally mountedon head 8 which clamped to the mud guard bracket lil, or the vehicle,vand the engaging` surfaces ot these members` (5b-8b) are provided withfriction discelements 9* 'that are held in elastic pressure contact witheach other by the spring washer and bolt connections 10"- 14. fr tensionspring l5 is connected to the lower end et the-link arm 5b, and subjectsthe latter. to an inward pull that is just suiieient to overcome thestatic or starting `friction between the disc elements 9 when the systemis compressed and the parts move from the 'lull line position N-J/Ltoward the dotted line position (al-0. lNhen the stressed suspensionmembers return from their compressed position, the pull oi" the springl5, supplements the action ot the frictionally engaged parts 8"-9l inresisting the outwardswinging movement of the link support 5b andthereby retards and damps the `tree recoil oi the coacting leaf springsl and l. When the parts have resumed their normal or static loadposition the link 5 is engaged by the adjustable stop G" on the head Sb;and when the body and :i1-le parts i, 'e subjected to a rebound or ei;-pansion n'iovement this suspension element is locked against furtheroutward swing, and the vertical separation ot thehead 8b and the aileperch 3 imposes an endwise stress on the bowed spring` 4i and pulls itstraight-as indicatedby the dotted lines 'rm/r oit Fig. fl. rllheelastic resistance ol the secondary suspension elements to thislongitudinal pull subjects the chassis members to a progressivelyyincreasing restiainiy that rapidly checks any abnormal separation oitthe spring supported parts land the symmetrical action oit thesestressed springs on the opposite sides of the body strongly resists anytendency to side sway, and holds the tonneau members properly Acenteredon their running gear supports.

ln the organization illustrated in Figs. 5 and G, the inner eye ends otthe secondary leatl springs l are carried by the upper arms of bellcrank shackles 5C; and these shackles are pivotally mounted onclipsSCpthat `are clamped to the central body portion oit the mainspring l. The lower arms ofthe bell crank elementsy 5C extend inwardlyunder the bottoni leaf ot the main spring, and are provided withlongitudinally curved grooves or pockets to receive and retainhardenedblocks or rolls, 9C, that are adapted to move outwardly and downwardly7under the effect et gravity, when the system is compressed and the partsmove from the normal load position (shown in tull lines in Fig. 5)toward the position Cc (shown in dotted lines in :Sand in full lines inlig. t). llhen the compressed sus aension members begin their returnincrement the l'ree recoil of the supplemental spring el is retardedboth by the lrictional drag ot its superimposed leat eieinents on eachother, and also by'thep sliding, er rolling7 engagement ot the mem- CTIparts toward the dotted` line positions.

BMW of Figs. 5 and G-is then immediately restrained and checked by thelongitudinal or endwise stress on the bowed supplemental leaf springwhich tends to straighten it out to the form shown in the upper portionsof these illustrations. The other functions of the secondary suspensionelements-in absorbing minor kinetic shocks and jars and in resisting andarresting side sway at all times in the oscillatoryA movements of thelsystem-are exercised in substantially the saine manner as in theanalogous organizations previously described.

Figs. 7, 8 and 9 show another arrangement of elastic suspension membersin which the ends of the main cross leaf spring 1 are shackled to `theouter extremities of forked lever elements tEd-2% and these levers arepivotally supported, at intermediate `points in their length, onsaddles, 3, 3d, which are clamped to the front Vaxle of the machine.

The inner ends of these levers are rigidly connected to the outer endsof the supplemental leaf springs et-fl, and the opposite, or innerextremities of the said springs are carried by the swinging llinkconnections 5",

5, that are pivoted on the body bracket 8d,

and limited in their pivotal movement thereon by the adjustable stops6d, 6d. The swinging' shackle links, which couple the levers 2, 2d, tothe ends -of the main sprino', are provided with extensions 16-1G, whichare engaged by auxiliary tension springs 17-17 that are attached to themud guard brackets 123 of the bod7 frame. lhen the system is subjectedto compression theparts move from the normal or static load vpositionshown in Fig. 'l' to .that shown in Fig. S; and the supplemental leafspring 4d is flattened out by the transverse or bending stress te whichit is subjected bythe upward swing of the inner ends of the lever Ql. inthis movement of compression the length of the auxiliary springs 1T-17is not substantially changed, and these elements merely exert a constantinitialtensien on the shackle links at the ends of Ithe main spring. Butwhen the body and axle members of the chassis rebound or separatebelrond the normal load position lT-n ofFig. 7 and move toward theexpanded position Rr of Figs. S and 9-the" link connections '5L-5 areonce engaged by the stops GL-Gd and the separation of the saddle andbracket members, 3d and 8d, exerts a direct longitudinal .pull on theattached 'lever and link elements 2l--51 andon the bowed supplementalleaf springs tlattached thereto, and thus subjects these suspensionelements to an endwise stress thatvpulls them *out as shown in Fig. 9.rhe straightening out of the springs 4d rocks the outer ends of thelevers 2 downwardly from their normal load position, and theconcurrentnpward movement of the body and main spring 1 causes theshackle links which carry the extensions 16 tov swing upwardly untilthey are nearly in line -with the said outer ends of the levers 2d andwith the axis of the primary suspension element-as shown in Fig. 9. Inthis position of tle parts the body is vertically locked in its centralposition on the running gear supports and any further separation ofthese members is powerfully resisted, by the endwise strain in both thesupplemental springs 4d, 4d and also in the main spring 1. The reboundmovement of the body and the accompanying outward and downward movementof the link ends 16-16 also imposes an increased tension on theauxiliary springs 17, l'-as indicated by the dotted line R-r at theright of Fig. S-which not only supplements the action of the springs t,ad, in resisting and checking rebound and side sway, but which alsoserves to impose an added pull on the ends of the main spring and toreturn the shackle link supports therefor to their normal load carryingposition when the rebound movement is checked and abated.

Figs. 10 and 11 depict the outer portion of a side leaf springsupport-for the rear axle of the vehicle-which is provided with asecondary spring suspension similar to the one last described. In thisconstruction .the

outer end of the main spring 1s is coupled` `to the adjacent outer endof the lever member 2@ by means of an elbow shackle connection thatcomprises; a pair of links 1S, pivotedy to the arm 19 and engaging theopposingv lface of the main spring.- The intermediate portion of thelever 2@ is flexibly supported on the bracket 3e that is clamped to thebod)7 support; and the inner extremity of the said .lever is rigidlysecured to the base portions of two supplemental leaf springs 4e whichextend inwardly-one on each side of the main spring ls-and are supportedat their eye ends by a link connection hat is piv ojted to an Vaxlebracket Se and limited in its arcuate movement thereon by an adjustablestop Ge. yIn this construction the lever 2 is also provided with aneccentric friction dog 2O which is pivoted to the swinging member and isheld in pressure engagement with the adjacent curved face 21 of the bodybracket 3e by means of the spring 22 (as best shown in ythe sectionalview of Fig. 11). When this system is subjected to compressive stressthe arm 19 is held in engagement with the outer end ot' the main springby the pressure of the applied load; and the thrust on the links 18rocks the arm 2e in a clockwise direction on its bracket support Se,applies an increased transverse bending stress to the supplementalsprings da, and straightens out the latter to the form shown by thedotted lines c-c of Fig. 10. The clockwise movement of the lever 2cpermits the dog 20 t-o swing inwardly under the pressure of the spring22; and when the return movement starts the reverse rotation of thelever-and the accompanying recoil of the stressed suspension elementsI#le-is retarded and damped by the sliding frictional engagement betweenthe curved surfaces of the dog 2O and the bracket face 21. Then theparts rebound or separate beyond the normal load position-- shown infull lines in Fig. 10*the stop 6e engages the bracket Se and thesupplemental springs ete are subjected to a longitudinal or endwisestress, that has the joint effect ot again rocking the lever 2ein aclockwise direction and of stretching or flattening out the bowedsecondary suspension elements to j the 'form indicated by the dottedlines r-r ot Fig. 10, AIn this rebound movement the lend oit the mainspring 1s is relieved of stress by the opening out of the elbow4 shackleconnection 18--19 (as shown in Fig. 11) against the tension of thespring 17e; and the free recoil of the stretched springs 4f is checked',as before, by the ri'ctional engagement of the parts QO--21-22- I Fig.12 illustrates another side leaf spring suspension system in whichthevrelative ar rangement and action of the main and suppleinentalspring elementsv is substantiallyV the saine as in the constructionot`Figs. l. and 2. When this systein iis subjected to kinetic compressivestress the parts are moved from the full line positions ot Fig. 12toward the upper dotted line positions VC---c ot that ligure-the lever2f being rocked in` a countercloclnvise position through an angle, zr,for the extreme move` inentfand when the body'and axle members reboundor separate beyond the position ot static equilibrium the link 5f islocked against the pull oi the supplemental spring el* (by theadjustable tie connection Gf) and the .latter is stretched or flattenedout to the torni shown by the dotted lines 7"---15 while the lever 2f iscorrespondingly rocked through the angle a. Y

F ig. 1B illustrates the application ot mj improved secondary springsuspension to a main' cantilever spring support for either the front orrear axle eta motor vehicle. .ln this application or exeuaplitcation et'present invention the usual coupling between the outer end ofthe mainVspring and its axle connection is removed, and'replaced by the shacklelink and clip. elements 18g-192% which serve to ieXibly couple the saidmain spring 1SS to the intermediate portion of a lever that is pivotedto the axle block 3g.

"lhis axle block is preferably provided with pair of tie bars or radiusrods 23, which eX- tend inwardly-one onjeach side ot the mainv guidethat slides in the slot 5g, t the adjust-` able bracket Sg, on the bodytrame. When `the system is subjected to kinetic compres-` sion stressthe parts are moved 'from the normal full line position of Fig. 13 tothe dotted line positions CMG of that illustration; andduring thismovement the inner end of the secondary leaf spring element .slides in`wardly along the slot But when there is reboui'id orseparation ot t-hebody and axle members, beyondv or above normal load pcsition, N, thecross guide at the end of the spring 4g engages with the forked outerend 6g ot the adjustable bracket 8g; and there is a' longitudinalpullexerted'on the opposite ends of this spring which pulls it and itslever support 2g into the dotted line positions r-a-r ci the figure. H

In all ofV he organizations `thus far described the secondary suspensionelement is made inthe form' of an initially bowed lea-Tt spring which isl'exed'and straightened out `under an increased load by a transverse orcrosswise bending strain and which vis stretched and 'straightened outunder rebound stre'ss by a longitudinal or endwise pull on its oppositeends.. But my invention is also genericallyv embodied in an organizaftion in which helical coil springsot either the open coil compressiontype or the closed coil expansion tyV e may be employed as secondarysuspension elements. f Examplesv otk suchi embodiments are `presented 1nthe" illustrations ot Figs. 14 to 31 inclusive.

In the combination'sho'wn in Figs.' 14 and 15, a main. cross leaf'spring 1 is shackled at its ends tothe intermediate portions ot' leverelements' 2h, 211,'which .are pivotally mounted on they reversed axleperches f2s-'3,

and which arelexibly coupled at their inner extremitiesto the upperheads 25, 25 ot the nested coil springs iL-4h11. These heads 25 .areslidably mounted on the swinging link lo Wer Y ian to` receive across'pin to which one end ot a iiexib'le strap 28 1s secured; and theVopposite end of this strap is connected to an adjustablev bolth that isheld in fixed rela'- tion' ito the main' spring and body assemblyby'l'li'e clip 29. I

lVhen the above described system is subjected to a kinetic compressionshock, or to a temporary increase' in load, the parts move trom the fullline positions N-n ot Fig. la toward the positions C-c shoivnin Fig. 15.During this movement the links 5 are 'swung inwardly, and springs Fl-4hare further compressed against the lower heads 27 bythe coacti'on of theswinging lever and sliding head members 2l" and 25. VVhfenthe partsreturn to normal load position (Fig. 14) and rebound or separate beyondthat position, the further outward movement ot theswinging links 5, 5,is arrested by the action ot the strap connections QS-tSL-QQ l@ind theselinks4 are lield in fixed axial-relation to the body ot' theX'f'ehi'cle. But the upper heads Q-Q, and the upper ends ot thesupl'alel'n'en-tal sp' ings lh-'lm carried thereby, are also held at aii'xcd distance from the axle perches 3-"3, by the rigid lever elementsQhf-Qh. Any separationo't the body snpp'ort'h for the links, and vontaxle support 3 tor the lever, willtheretore draw theheads 25-27 towardeach other and correspondingly compress the secondary suspensionelements-as shown by `the dotted line movement 'ri-f1" or mr ot Fig. 14.

The rebound movement from 'ln-n toward 1"-0) will therefore be resistedand checked both by the increased positive compression ot thesupplemental springs against the link supported heads iXi-27, but alsoby the frictional side dra-g ot the 'sliding heads 25-25 on the edges ofthese supporting links. The longitudinal stresses in the symmetricallyinclined lever'members 212, on `the opposite sides ot the body, will@also hold that member of the chassis centered on the running gear, andwill prevent, l or qr'i'ickly extinguish, any side sway or rolling ofthe vehicle tonneau. p

Figs. 1G and 17 illustrate a` construction which is very similar intorni to the one last considered and which will therefore not requireany detailed description. "When the system is compressed the swinginglink elements 5i rock in vardly on the pivot supports SMwhich are, inthis case supported on intermediate portions ot' the main lea't springl-and the 'supplemental coil springs All are compressed against theiixed heads 27i (as shown in full lines in Fig.- 17). .llhen the partsreturn to normal load position (Fig. 16) rand rebound beyond thatposition (see dotted lines R 1 ot Fig. 17) the upper ends ot the links5'* are. engaged by the adjnstable stops Gil; and the downward pulll ofthe levers 2i on the sliding heads` QV# agafin subjects the secondarysprings to an increased compression which reactivcly restrains theexpansion oit' the system.

The organization shown in Figs. 18, 1S) and 2O is one in which each olithe secondary suspension elements comprise two coil springs, one otwhich is an open coil compression spring fl, and the other ot which is anormally closed coil expansion spring lld. These springsv areoperatively connected, at their adjacent extremities, to common heads,

25.1,wh'ich slide longitudinally on the link,

rods 5k, and are respectively conjoined at their opposite extremities tothe heads 27 and 27kk which aire i xed to the outer and inner ends or'the said link r`ods.- The last named' elements are pivotally mounted onthe body brackets Sk, and are limited in their arcuate movement withrespect thereto by adjustable bolt and strap y connections 6f-2`8". Thehea-ds Q5 are flexibly coupled to the inn-er ends ot levers 2k, whichare pivotally 1nonnted-near their centers-on axle brackets 3, and areshackled,l at their outer ends, tol the extremities oit the main spring1l lVhen the system is kinetically coinpressed the various operatingparts move from the normal load position (ot static equilibrium) shownin Fig. 1S, toward, or to, the position shown in Fig. 19-therebyimposing. an increased compression strainfon the supplemental springs l,and a correspondingly increased tension strain on the springs 4k andwhen the' body and axle members rebound or separate beyond normal loadposition (Fig. 18) the link connections 5k are held in iixedrelationship to the body, the heads 25k are drawn outwardly on the fixedlink rods, by the longitudinal pull of the lever arms 2, and anincreased tlexure is again imposed on both ot' the secondary suspensionelements 4l and 41k (as Ashown vin Fig. 20.) It will be apparent that inthis construction-as in all ot the previously described applications otmy invention to cross lea'f spring systems-the body ot the vehicle is,atv all times', subjected to the influence otoppositely ydirected andcentrally applied forces, which act through the symmetrically disposedand inwardly inclined lever elements (2) 21?, and that by reason ot this'action any side'swing, or rolling ot the tonneau, with respect to itsrunning gear supports, is either entirely prevented, or is veryettectively restrained and abated; and it will also be apparent thatthis restraint becomes more and more powerful as the separation, orexpansion, movement increasesin magnitude; and that, when any excessiverebound occursas shown in Fig. 2O (or in corresponding Figs. 2, 9 etc.)

the body member is virtually locked against lateral displacement,` onits support system, by the compression or extension of the supplementalspring elements to the limit of their flexural movement.

JAttention has already been .directed to the fact that in the operationof the species of construction shown in Figs. 14; to 19 inclusive, theresilient restraint of the elastic elements 4th, li or 4k, issuppleinented--partieni-arly on rebound or separation of the body andaxle inembers--by the frictional rest 1aint to the sliding movements ofthe heads @Fi-2:? or 25 on the link guides 5, 5l

or 5k. rllhe frictional restraint on all recoil movements may beincreased, if desired, by the use ofthe devices illustrated in Fig. 2l.ln the detail construction there shoivn the hub of the sliding head (e.the head 25k) is provided with a conical recess, which is adapted toreceive a split or divided sleeve 9k, that isheld in light pressureengagement with the face of the recess by a spring 10- interposedbetween the larger end of the sleeve and an adjustable plug 30 in theend of therecess. `When the head moves in the direction of the arrow-,orin a direction to produce an increased lexni'e of the secondarysuspension elements-the pressure of l the split sleeve on the surface ofthe link guide (e. gx, 5k) is relieved, and the frictional grip of thesliding head on this guide isi'educed; but when the return or reversemovement occurs, the action of the sp ing (10k) forces the dividedsleeve (9k) into the conical recess of the head (25k) and against thesurface of the link rod (5k), and the drag of the moving head on thelongitudinally lined link connection is substantially increased, therebyretarding or damping the free recoil of the stressed secondary springs.

Figs. 22 and 23 illustrate a side leaf spring system which is providedwith a frictionally damped secondaryy spring suspension that is quitesimilar in form to the one shown in Figs. 18 toV 21 inclusive. In theorganization nonT under consideration the lever clement, 2 comprises apair of arms which are pivotally mounted, at an .intermediate point intheir length, on the usual scroll bracket 3m of the bod-y frame; arebolted together at theirl outer ends and are there shackled to theadjacent extremity of the main spring l. by means the links 18m, therock bnr 19T, and the saddle 3,1; and are pivotally connected at theirinner ends to heads 25m that are slidably mounted on a pair of guides 5mwhich are syn'nnetrically disposed on opposite sides of the main spring`The links 5m. are rockablyvsupported, as a unit, on an axle bracket 8,and are limited in their rocking movement thereon by the adjustable andflexible Connections @N Qlm that are attached, respectively, to the axleframe and to the cross head 32 that couples together the lower ends ofthe link elements lim. The secondary suspension springs of thiscombination consist of a pair of normally closed tension coils lm Whichsurround the guide rods 5m and are attached at opposite ends to thesliding heads 25m and the lined head 27m of this guide link connection.When this system is compressed the parts inove from the normal loadpositions in pressure engagement with the saddle sup-4 port 31, and thethrust of the shackle links 18m rocks the lever 9) through'the angle,e?, (in passing` from the positions of Fig. 22 to thosey of liig.thereby stretching the supplemental springsto the extent indicated inFig. Q3. ln the rebound or expansion movement, from positions N--vi tokpositions l-r, the link connections 5* are locked on their .bracketsupports and theV diagonal pull of the leverr elements on the heads 251,again stretches the tension springs ,t to subst-an# tially the sainedeg-ree as the first considered movement. This action rocks the levermembers 2* through creased arcuate movement is permitted- Withoutimposing' any reverse flexure on the main spring-by the lifting of theshackle bar 19m from its saddle support 3l. At the end or limit of theindicated rebound (re-r) the shacklelinks 18m and `the shackle bar 19mare drawn into substantial alignment with the main spring is; (seedotted line diagram R-r r at the upper left hand side of Fig. 23) andthen exert a direct endvvise pull or tension on the main suspension member that tends to supplement the imposed tension on the secondaryelements, 4m, in resisting abnormalV or unusual expansion movements ofthe spring connected parts.

Figs. 2t, Q5 and 26 depictA another combinationV of ay main side leafspring With a pneumatieally damped secondary .spring suspension. ln thisconstruction the lever elements 2 con'ipiises tivo tivin arms pivoted attheir outer extremities to the body bracket 8. and extending doivn--oneon each side of the main spring SLL-to the loiver entreinities ln the anangle, s; and this in-A lll() iio of tul'iular members 33 that arerigidly secured to the opposite ends of the cross-bolt 250 on whichthevinner ends of the armsv 20 are pivoted. (see Fig. 26). The tubularmembers 33 are engaged by hollou7 piston elements 34 which are pivotallymounted on a cross bolt 27 that` is carried by the axle bracket 8; and apair of open coil conipression springs l0 are interposed between theopposing closed ends of the slidably ena menjibersBS--Sfh which togetherform :i swinging .link Aconnection between the lever and axleuai-ts ofthe system. The upper h *ads ot' the piston elements-34 are providedwith vents which are closed by the outwardly opening flap valves 36; andthe interior ot the spring receiving chambers may be partially lilledwith a thick oil or other viscous liquid that serves both to protect thesprings, llo, lubrieate the sliding parts 33 34, and reduce the airspace in the said chambers, -tor the purpose later described, rlfheintern'iediate portion ot the crossbolt 25" is provided with a spacingblock 32 that is flexibly connected. to the axle assembly by nlieans ot'a strap 28 and an adjustable angle trame o". rlhe median portion ot' thelever 2 is ca'iupled to the adjacent eye end of the main spring l5, bymeans ot' a spring actuated elbow shackle, similar to that shown inFigs. l() and ll, and comprising the links 180, the bar 190 and the leatspring 17 which is engaged at its opposite ends with the bar 19 and theouter extremity of the lever 2".

The detail operation oi the organization ast described is verysiiniiarto that ot the analogous arrangement slimvn in Fig. l2. `Whenthe system is compressed the lever 2" is rocked in a connteiclockwisedirection on its main pivot support, and in passing from the normal loadposition (hl-n) ot Fig. 24. to the extreme load positionv (Ce-c) ot F 25this memberdescribes the arc, te, and compresses the springs lo toalmost of their normally tensioned length (Figs. 2a and 26). lasl themembers 33 and move together, the air in the spring enclosing chambersis expelled through the valve openings Sii-36; but when a re-A versemovement occurs these openings automatically close, and the separationot the heads' 25? and 27creates a partial vacuum in the expandingchambers that tendsA to pneumatically check the recoil ot the compressedsprings 4:". Vhen the parts have returned to normal load position (N-nof Fig. 2l) the strap and angle :trame conneetions 28-6 are brought intotensioned engagement with the block 32"; and when any rebound, orseparation of the chassis members.l occurs the pulll of theseconnections rocks the lever arms through the small angle and draws theminto substantial alignment with` the strap 28, while tl erelativedownward movement of the axle bracket 8, the heads 27 and thepiston ele'- nients 3ft (trom N-a to R-r) again compresses the secondarysprings l" to substantially the same degree as they are flexed by' thecompression movement trom N-n to C-c. ln this case the recoil or returnolf the parts from the position of extreme rebound is retarded anddamped by the ac'- tion of the partial vvacuum produced in thespringenclosing chambers when the coinpressed secondary element-s beginto expand.

Figs. 27 and 2S show a further exempliand is limited in its angularmovement by' au adjustable stirrup 6I that passes around the axle. rl`heupper end of this elastic `suspension element. is engaged by the head27, thatis attached to the movable connection rod, 38, and is guided inits movement. bythe radius arm 39; and the opposite ex tremity ot thesaid element is supported by the head 25p which is prorided with anelongated hub that can slide longitudinally on the rod 88. rlhis lowerhead 25,1 is pivotally attached to the forked extremity ot a tie arni2,that extends upwardly to the body frame; and the length of this arm is,so adjusted (as by the bolt and nut connections #1040) that when theparts are ir. normal load position (Fig. 27) the head 25p is supportedon the foot of the L-shaped link traine 5P. The lower end of the guiderod 3S is slidably engaged in the support ing loot ot" the link trame,and is provided Vith anenlarged boss Lll that limits its upward movementtherein; and this boss is saackled to the adjacent eye end of the mainspring member 1.

rlhe operation of this last described exeinpliiication of my inventionis generically identical with that of the previously consideredembodimentsy thereof. When the chassis members are :forced toward eachother by a temporary increase in load stress, the suspension springs 4.1are compressed by the downward pull of the main spring shackleconnections on the rods 88, while the 'frames 5P are yrocked away fromthe body by the outward thrust of the tie arms 2p; thus moving the partsfrom the normal load position oit Fig. 27 toward, and ultimately to, theposition of compression shown in Fig. 2S. When the system is restored tothe condition ot static equilib riuin the stirrups Gp engage the axlemeinber and prevent any further inward move-- ment of the linkyirames 5Ion their axle supports; and the bosses 41 engage with the link framesand prevent any further rise of the guide rods 38. Any rebound orexpansion ot the spring connected parts imposes a longitudinal pull onthe diagonal tie arm connections 2D, and this, in turn, lifts the lowerheads 25p away from the supporting feet of the frames 5P andcorrespondingly compresses the springs 4p against the upper heads QTP-asshown in Fig. 29. The oblique pull of the symmetrically inclined tieconnections 2P-2P on the opposite sides of the body frame restrains anylateral sway of that member on its running gear supports; and thisdiagonally applied tension on the sliding heads 25p also increases thefric-l tional Cdrag of these part-s on the axle supported elements.3S-5P and thus steadies and clamps the oscilla-tory movements of theelastic suspension members ofthe system. The frictional damping ofrecoil oscillations may be further increased, to any desired extent, byproviding the hub portion of the head 251 with a one Way friction gripdevice similar to that shown in Fig. 2l.

rlhe final illustrative embodiment of my present invention (Figs. 30 and3l) is quite similar in form to that just considered and will thereforebe readily understood Without extended description. The various parts ofthis embodiment are shown in their normal load position (staticequilibrium) 'in Fig. 30. llVlien the supplemental suspension system issubjected to a kinetic conipression stress the resultantmovement of themain spring and body toward the axle, and the accompanying outwardmovement ofthe L-Shaped link frame 5 on its axle perchsupport 3G-underthe thrust of the body connection ,2L-carries the parts toward thepositionvshoivn in Fig. 3l. This movement expands or opens up thesupplemental spring shackles d which couple the end of the main spring ito the loiver head 251 of the supplemental coil spring d, but does `notvary the initial tension of the latter element, because the headl 25 isat this time supported .on thelink frame 51, and is held against lateraldisplacement thereon by the radius guide rod 391. But when the kineticcompressive strain is relieved, and the spring suspension elements havebeen returned to normalload position (Fig. 30)- by the closing of theexpanded spring shackles eq, and the relative upward movement of thebody of the vehicle-the adjustable .stop 61 on the frame 51 engages withan intermediate portion of the main leaf spring l; and any rebound orseparation of the spring connected chassis members then imposes alongitudinal tension on the arm 2q Which lifts the radius guide arm 39C1and j the head 25 toward the dotted line positions r-r of Fig. 30. Thismovement coinpresses the' initially tensioned coil spring Lllq againstits upper head 271'(ivhi ch is rigidly supported on the frame 51), andalso subjects the spring shackles lq to an increased bending strain,which is transmitted to the eye end of the main spring l and whichtends, in turn, to positively flex the outer portion of the latterelement against members;

the downward pressure ofthe link frame stop 6G. These concurrentiiexures of the two secondary springs, 4, llm, and ofthe main spring i,cooperate to powerfully resist and very quickly check yany abnormalexpansion or rebound of the ybody andaxle and the oppositely directedstresses in the symmetrically inclined arms 2, 2q, on the opposite sidesof the chassisV frame, restrain or prevent any side sway or lateraldisplacement of the tonneau with respect to lthe ruiming gear supports.

The general principles` of functional ac.- tion which characterize myimproved shock absorber organization and the manner in which thosecharacteristic features may be incorporated in a variety of structuralformsas illustrated, for example, by the different exemplificationshereinbefore presented-should now be clearly apparent7 to those skilledin this art, Without further eX- `planation; and with the foregoingdisclosure as a guide, engineers, and others familiar with theconstruction and use ofvehicle suspension systems, canreadily designother forms and arrangements of spring suspension elements (embodying inWhole. or in part my present invention), Which Will be particularlyadapted to special types or species of vehicle chassis, frames.` InsomeA my improvements in' which no special dampt ingV devices areemployed-it being understood that the forced restraint, and the.external retardation, of the `normal compres-I sion or expansion of theresilient suspension members is not an essentiall or necessary part ofthis invention. lt will also be yunderstood that the supplemental linkconnections (e. g., 5*"*i qq etc), and the means which I employ forlimiting the arl cuate or swinging movement of these conL nections, withrespect to their support` members, (e. g., the stops 6**1* GQ eta), maybe Widely varied in form and arrangement; and that the adjustments whichare provided for bringing said limiti-ng means y into action-at apredetermined point in the spring movement may in some cases bedispensed with, Without altering the essential operative characteristicsof my neuT combination of link frame-limit stop-spring-and leverlconnection elements, which conjoins the body and axle parts of thevehicle chassis and which acts to elastically restrain both vertical andlateral movements of their hicle body.

bination; and that I do not intend to limit myself to any specilicdetails vof organization, except as indicated in the appended claims;towit:

l. In a suspension system for two relatively movable members thecombination of an arm flexibly connected to one of the said members, alink support pivotally mounted on the other member, a spring operativelyconnected at one end to the said arm and at l the other end to the saidlink, and a stop for holding the link in fixed position with respect toits mounting when the said members are separated beyond normal loadposition.

2. In a suspension system for two relatively movable members tliecombination of an arm flexibly connected to one of the said members, alink support pivotally mounted on the other member, a spring operativelyconnected at one end to the said arm and at the other end to the saidlink, a stop for holding the link in rfixed position with respect to itsmounting when the suspension system is expanded, and means for adjustingthe position of the said stop.

3..A spring suspension system for vehicles which comprises a mainspring, an arm pivotally'attached to one of the relatively movablechassis members, a link frame flexibly mounted on the other of the saidmenibers, a supplemental spring conjoining the said armand the saidframe and cooperating with the said main spring to resist displacementsof the said members in either direction from the normal `load position,and an adjustable stop for holding the link frame rigidly withrespect-'to the member on which it is carried when the system isexpanded beyond normal load position.

4. In a shock absorbing system for vehicles a combination of a swingingarm secured at one point to one oit the relativelyv movable chassismembers and operatively connected at another-point to one end of asupplemental spring, a swinging link-frame flexibly attached to theother relatively movable chassis member, and operatively connected tothe opposite end of the said supplemental siring, and means whereby thesaid link i'rame is locked against movement with respect to its supportwhen the chassis niembers rebound or separate beyond their nor malloadposition.

5. A spring suspension systeinfor the relatively movable members of avehicle chassis which comprises a main spring, a rocking arm pivotallymounted on one of the said chassis` members, alink-rame flexiblyattached to the other of the said members, a supplemental springoperativelyV conjoined at its extremities to the said arm and the saidframe, and an adjustable stop adapted to lock the said frame againstlateral movementin the plane of sprin-OF suspension when the suspendedchassismembers are separated beyond their position of staticequilibrium.

6. In a supplemental suspension lfor vehicle springs the combinationofal secondary resilient member operatively connected at its opposite endsto the body and axle parts of the vehicle, means whereby the saidsecondary member is progressively flexed by the application of atransversely applied stress from the main spring when the body and axleparts oi' the vehicle approach each other, and other means whereby thesaid secondary spring is also progressively flexed by the application ofa longitudinally applied stress from its endconnections when the bodyand axle parts rebound .beyond their normal load position.

7. In a supplemental suspension for vehicle springs the combination of asecondary spring member, an arm operatively connect- `ed at one point toone extremity of the said secondary spring and at another point to oneof the vehicle members, a link frame operatively connected to the otherextremity of the secondary spring and flexibly supported on anothervehicle member, means conjoiniiig the main vehicle spring with one oftheparts thus operatively .connected with the secondary spring wherebythe latter is cooperatively lexed with the said main spring when thebody and axle members approach each other, and a stop engaging with thelink frame to prevent swinging movement on its support when the body andaxle members rebound beyond the normal load position.

8. In a shock absorbing system for vehicles the combination of a mainspring, an arm flexibly mounted on one of the vehicle members andshackled to the eye end'of the main spring, a link frame liexiblysupported on another vehicle member which is relatively movable withrespect to the first, a

stop for limiting the outward movement of the said link frame withrespect to its support, and a supplemental spring operatively conjoinedat its opposite extremities to the said arm and the said link.

9. A spring suspension system for avvehicle chassis which comprises amain leaf spring secured at the center to onek of the relatively movablechassis members, a lever pivotally mounted on the other of saidrelatively movable members and flexibly connected to the eye end of saidmain spring, a link frame flexibly supported on the first mentionedchassis member, means for limit ing the arcuate movement of the saidframe with respect to the said supporting member, and a supplementalspring operatively connected at its ends to the said lever and the saidframe.

10. In a spring suspension system for two relatively movable members thecombination of a main spring rigidly secured to one of said members, alever pivotally mounted at one point in its length on the other of thesaid members, and flexibly attached at another point to the eye end ofthe said main spring, a supplemental spring operatively connected tostill another point on the said lever, a link-frame pivotally supportedon the first mentioned member of the chassis and operatively connectedto another part of said supplemental spring, means for arresting theswinging movement of the flexibly supported link-frame when theaforesaid relatively movable members are separated vbeyond a certainpoint, and means for adjusting the point at which the said swingingmovement is arrested.

11. In a shock absorbing system for vehicles the combination of aswinging arm pivotally mounted on one of the relatively movable membersof the vehicle chassis, a second swinging arm flexibly supported on theother of the said members, means for pre venting the swinging movementof the said second arm with respect to its support-ing member when thechassis parts rebound beyond normal load position, and an initiallybowed leaf spring operatively connected at its opposite extremities tothe aforesaid arms. v

a 12. In a vehicle suspension system the combination of a relativelystiftp main leaf spring, a relatively flexible supplemental leaf springoperatively connected at its opposite ends to the body and axle membersof the vehicle, means whereby the said suppl-emental spring isprogressively flexed by transversely applied stress when the said bodyand axle members approach each other, and other means whereby thisspring is corr-espondingly flexed by longitudinally applied stress whenthe said body and axle member rebound or are separated beyond normalload position.

13. A shock absorber system for vehicles which comprises, thecombination of a main spring interposed between the body and axlemembers, an arm pivoted to one of said members, a supplemental springoperative- 'ly connected at one end to the said arm, means for exiblysupporting the other end of said spring on the other' of said members,

and means for holding the last mentioned end of said supplemental springin fixed relationship to its associated supporting member when thesystem rebounds or expands beyond normal load position.

14. A spring suspension system for vehicles which comprises, a mainspring ,interposed between the relatively movable chassis' members, anarm pivotally mounted on one of said members, a supplemental spring oplvehicle which comprises, an arm pivot-ally' supported on one of saidmembers, a link frame flexibly mounted on another of said members, asupplemental spring operatively connected at one end to the said arm andat the other end to the said link, and means for frictionallyrestraining the movements of the said link in one direction. l

16. A shock absorber for two relatively movable parts which comprisestwo members flexibly mounted one on each of the said parts, a springinterposed between the members and operatively connected thereto at'itsopposite ends, and means for frictionally retarding the flexing movementof one of said members when the parts are separated from one another.

17. In a spring suspension system for vehicles the combination of amember flexibly supported on the axle assembly, a second member flexiblymounted on the body assembly, a supplemental spring operativelyconnected at its opposite ends to the aforesaid members and acting toelastically resist the compression of the system, and a one way frictiondevice acting on one of said members to retard the expansion thereof.

r18. A shock absorber for vehicles which comprises the combination oftwo members flexibly mounted one on the axle assembly and the other onthe body portion of the vehicle, a supplemental spring operativelysecured at its opposite ends to the said members and acting toelastically resist the approachof the axle and body parts, means forfrictionally damping the flexing movement of one of said members whenthe said parts separate from each other, and other means for holding oneof said `members against flexing movement with respect to its mountingwhen the body and axle rebound beyond normal load position.

In testimony whereof I have hereunto set my hand.

FRANK L. O. lVADSl/VORTH.

